Objects clipping when I switch to orthographic mode Blender 2.8
I've been having the same problem and fortunately we are not alone and somebody has already reported this bug. You can find the current state of it at the link below. It looks like it's been resolved and we're just waiting on an update now.

Bug report
https://developer.blender.org/T61632

Specific commit with the fix
https://developer.blender.org/rB4bbd1b9610f6d85079ea5bc31fc1949f8409a1a4